1. Field of Invention
The present invention relates to the LED technical field, and more particularly to an LED package structure for reducing the internal heat conduction resistance of an LED light module or an LED chip as well as raising the insulation strength thereof.
2. Description of Related Arts
One of the most important applications of LED technology is the light illumination. The LED light illumination is considered to be the green illumination technology for the next generation of human beings. However, the manufacturing costs of LED illumination products are still high, so that the widely application thereof is hindered. The heat dissipation should be responsible for the high manufacturing costs of LED illumination products. The LED heat dissipating process comprises an internal heat conduction process, and an external heat transfer process of air convection (and/or radiation). The present invention only relates to the internal heat conduction process.
The internal heat conduction thermal resistance of a current LED chip accounts for a relatively large portion of the total heat transfer process thermal resistance. A current product has a thermal resistance of at least 6° C./W. The amount will be at least 10° C./W considering the thermal resistance of the insulation layer on the aluminum base plate. The aim for addressing the electrical insulation problem within the chip should be responsible for the high internal conduction thermal resistance. Even the internal conduction thermal resistance is as high as the amount mentioned above, the electrical insulation strength thereof is less than 2,000V. The thermal resistance must be higher for obtaining higher and safer electrical insulation strength. There is suggestion which is to adopt a high heat conduction ceramic (such as AIN ceramic) as the heat sink of the LED chip for solving the contradiction between the insulation and heat conduction issue. However, the manufacturing costs of AIN like high heat conduction ceramics are high.
The modularization and standardization of light source is the inevitable development orientation of LED light illumination. A Chinese patent (patent No. ZL2009201340352, an LED lamp core and LED illumination lamp thereof) adopts a conical or tapered spiral column structure to solve the problem of contact heat transfer between the LED light module and the lamp (radiator). But the contradiction between the electrical insulation and heat conduction issue from the LED wafer to the heat conductive core (lamp) remains to be solved.